The overall aim of the proposed investigation is to examine the efficacy of a cognitive-behavioral treatment (One- Session Treatment; Ost, 1989a) in reducing symptoms and sequellae of Specific Phobia in children and adolescents. Findings indicate that clinically significant specific phobias are present in approximately 5 percent of children in community samples and in about 15 percent to 20 percent of children presenting at phobic and anxiety disorders clinics. Furthermore, findings indicate that clinic-referred children who present with specific phobias in specialized clinics are likely to be co-morbid with other anxiety disorders, affective disorders, and disruptive behavior disorders. For many children, the phobia results in considerable academic, social, and personal distress, as well as interference in day-to-day activities. Phobias may persist for a lifetime. One-Session Treatment has been found to be a rapid and effective treatment for adults with phobic disorders. Surprisingly, this treatment has not been evaluated in countries other than Sweden, and its utility in the treatment of childhood phobias has not been examined. A systematic evaluation of its efficacy in Virginia and Sweden is proposed. Specific aims are threefold: 1) to evaluate the efficacy of One- Session Treatment with children in a controlled, randomized trial; 2) to undertake systematic evaluation of its efficacy in Virginia and Sweden; and 3) to explore predictors of treatment outcome, including parental psychopathology, over-involved parenting styles, and child co-morbidity. One-hundred-and twenty children in Virginia (60 boys, 60 girls) and 120 children in Sweden (60 boys, 60 girls) between 8 and 14 years of age and meeting DSM-IV criteria for a primary diagnosis of specific phobia will be randomly assigned to One-Session Treatment, Education/Support, or Waitlist Control conditions. Following the waitlist period, children still meeting criteria for a Specific Phobia in the waitlist control and the Education/Support conditions will be provided One-Session Treatment. Depending upon remission and attrition rates, this strategy will permit a relatively robust examination of the efficacy of One-Session Treatment, its systematic evaluation in Sweden and Virginia, and the predictors of treatment outcome. As such, the present investigation will build on strengths in the current literature by using cognitive-behavioral procedures that have some, albeit limited, support in the treatment of phobic children (Ollendick and King, 1998, in press). At the same time, it will address shortcomings in extant studies by examining a treatment not studied heretofore with children (but with considerable support for its use with adults) and by examining the role of parental psychopathology, parental over- protectiveness, and child co-morbidity in moderating treatment outcome. Effectiveness studies in "real-world" clinical settings (Hoagwood, Hibbs, Brent, and Jensen, 1995) await results of this more laboratory-based controlled trial.